fix(sdk): skip empty REST update when only toggling PR draft

.changeset/update-pr-draft-only.md

@@ -0,0 +1,5 @@
+---
+'@github-tools/sdk': patch
+---
+
+Skip the REST update when `updatePullRequest` is called with only `draft`. Octokit was sending an empty PATCH body (`''`), which GitHub rejects with 400 before the GraphQL draft mutation could run.

packages/github-tools/src/core/pull-requests.ts

@@ -128,7 +128,10 @@ export const updatePullRequestDescription = 'Update a pull request — title, bo
 /** Not idempotent — each call applies a new revision. */
 export async function updatePullRequestCore({ token, owner, repo, pullNumber, title, body, state, base, draft }: { token: string, owner: string, repo: string, pullNumber: number, title?: string, body?: string, state?: 'open' | 'closed', base?: string, draft?: boolean }) {
   const octokit = createOctokit(token)
-  const { data } = await octokit.rest.pulls.update({ owner, repo, pull_number: pullNumber, title, body, state, base })
+  const hasRestUpdate = title !== undefined || body !== undefined || state !== undefined || base !== undefined
+  const { data } = hasRestUpdate
+    ? await octokit.rest.pulls.update({ owner, repo, pull_number: pullNumber, title, body, state, base })
+    : await octokit.rest.pulls.get({ owner, repo, pull_number: pullNumber })
 
   if (draft !== undefined && draft !== data.draft) {
     await octokit.graphql(draft ? CONVERT_TO_DRAFT_MUTATION : MARK_READY_FOR_REVIEW_MUTATION, { pullRequestId: data.node_id })

pnpm-workspace.yaml

@@ -35,4 +35,5 @@ minimumReleaseAgeExclude:
 overrides:
   '@ai-sdk/vue>ai': 7.0.70
   '@ai-sdk/workflow>ai': 7.0.70
+  'undici@5': 6.28.0